AA/AAA Battery Dispenser + Dead Bin - Backstage cart lip (one piece, strongest)
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What it holds: 2 x 12 AA with caps on, plus the DEAD cup holster (detent grooves; needs ~210 mm headroom to lift the cup)

PRINT SETTINGS
  Filament:  PETG
  Walls:     5
  Infill:    35% gyroid
  Orientation: the files are already oriented for printing. Put them on the plate as they load;
               don't rotate them.

FILES AND SUPPORTS
  - clip_LB_AA_AA_battery_dispenser_AA_AA.stl  (supports: no)
  - clip_LB_dead_cup_dead_cup.stl  (supports: no)
  - clip_LB_cap_DEAD_dead_bin_lid.stl  (supports: no)
  - clip_LB_cap_AA_fresh_cap_AA.stl  (supports: no)
  - clip_LB_AA_AAA_battery_dispenser_AA_AAA.stl  (supports: no)
  - clip_LB_cap_AAA_fresh_cap_AAA.stl  (supports: no)

HOW IT MOUNTS
  BACKSTAGE CART LIP (ONE PIECE, STRONGEST)
    The cart-lip slot is printed into the holder, so it is one piece and as strong as it gets.
    Hold it tilted, hook the slot over the upright lip on the edge of a Magliner / Backstage-style cart
    shelf, and rock it down until it sits flat against the side.

    Notes for this holder: Default: one piece with the Magliner/cart lip block (shipped part), strongest. Prints upright with build-plate tree supports under the inner flange. Print the dead cup, its red lid and two FRESH AA caps. Also included: other sizes and parts (clip_LB_AA_AAA_battery_dispenser_AA_AAA.stl, clip_LB_cap_AAA_fresh_cap_AAA.stl).

HOW IT WORKS
  Battery station for sound, camera and script carts: fresh AA (and AAA) cells feed out of the bottom oldest-first, and a separate DEAD bin keeps used cells out of the kit.
  How it works: load fresh cells at the top of a column, lying along the cart edge. The bottom cell rolls down a 10 degree floor, under the front wall and into an open pick tray. Pinch it out by its ends: there's a finger scoop in each tray end wall. The next cell then rolls into the tray. You can see the stock through a 6 mm window with a tick every 4 cells.
  Stays put on a bumpy push: the tray floor is 3 mm below the column exit, so the cell behind pushes the tray cell down into the tray, not out of it. The tray's front stop lip is 8.7 mm tall for AA and 6.3 mm for AAA (0.6 x the cell diameter), and the end walls come up past the cell's axis. Snap caps close the column tops so the top cell can't bounce out on a lift-gate drop. Each column has 9 mm of head room above a full stack, so the cap always seats on a full column.
  DEAD cup: dead cells go into a separate lift-out cup that sits in a holster on the dispenser. Its red snap lid has a coin-style drop slot (16.5 x 52 mm) for AA or AAA. To empty it, hook a finger through the tab on the front of the cup, lift it straight up, tip it out and drop it back in. The dispenser stays on the cart and the fresh cells stay put. Two small bumps near the top of the cup click into grooves just under the holster rim, so it can't hop out on a lift-gate drop. The bumps only touch the holster for the last 6 mm, so the cup slides freely the rest of the way. A slot in the holster floor lets you push the cup up from below. Headroom: the cup is about 160 mm tall and comes straight up out of the holster, so you need about 210 mm of clear space above the deck at the DEAD end to lift it out. Don't fit the dispenser under a shelf or overhang closer than that.
  Versions:

  - AA + AA: 2 x 12 AA with the caps on (11 in each column + 1 in each tray), plus the DEAD cup (about 15-20 cells)
  - AA + AAA: 12 AA + 16 AAA with the caps on, plus the DEAD cup
  - Print separately: the DEAD cup (fits both dispensers), the FRESH AA cap, the FRESH AAA cap and the DEAD lid. Print the DEAD lid (or the whole cup) in red.
  - FRESH / AA / AAA / DEAD are raised on the front faces. Use a contrasting colour change or paint pen if you like.
  Cart facts

  - Sticks out from the cart side: 26 mm at the columns, 44 mm at the trays and the DEAD holster
  - Hangs below the deck: 134.5 mm. The column tops are level with the mount top (42 mm above the deck), and the DEAD cup's lifting tab stands up to 50 mm above the deck.
  - Flat cart side needed below the lip: 45 mm. Below that the back is set 2.5 mm off the cart side.
  - Lift-out headroom: about 210 mm clear above the deck over the DEAD holster (the cup bottom has to clear the 30 mm holster rim)
  - Weight when full: about 0.6 kg of cells, all within 44 mm of the cart side
  - Two M5 insert holes
  Retention: held by gravity unless you fit the M5 thumbscrew. A short M5 heat-set insert (6.4 mm hole, 9 deep) goes into the deck-side face of the inner flange; a nylon-tipped M5 thumbscrew through it clamps the lip, so the part cannot lift off on a bump, slide along the lip or rattle. Check your lip is at least 16 mm tall first.
  Fits: Backstage Equipment and Magliner-style carts with a 3.4 mm upright shelf lip. The mount drops onto the lip from above: 3.7 mm slot (0.3 mm clearance), 26.6 mm deep with a round end, 0.5 mm chamfers at both slot ends.

OTHER MOUNTS
  The same holder also comes ToughBuilt bar (one piece), Dock (swap between mounts), Mountless (desk, shelf, case or screw to a panel). Pick the mount on the site: https://cart-tools.sdos-placeholder.workers.dev/#lb-aa-aa-battery-dispenser-aa-aa

TEST THE FIT FIRST
  Carts, bars and tape rolls vary a little. Before a long print, print the small fit test from the
  Test pieces section of the site (or this part at low infill) and check it on your own gear.

Not affiliated with or endorsed by Magliner, Backstage Equipment, ToughBuilt, Milwaukee, Hollyland, Eartec, Sekonic, Inovativ, Matthews or Manfrotto. Brand names only say what a holder fits.
